Two-step degenerate four-wave mixing as a means to decrease pre- and post-filtering effects in optically thick media

摘要: The use of crossed beam 2-Step Degenerate Four-Wave Mixing (2S-DFWM) for decreasing pre- and post-filtering effects under optically thick conditions has been investigated. 2S-DFWM is a technique in which the DFWM process performed between two excited states lower one populated by an ordinary laser excitation from low lying, highly state. Experiments were on Au acetylene/air flame. We have shown that where (one-step) experiments are significantly affected (i.e., partly absorption pump, probe or signal beams prior to after interaction region) can give virtually interference free signals. A variety different flame configurations It was found geometry, first step exciting incident upon region perpendicular beams, completely eliminated severe occurring single-step scheme medium.